I would recommend hightlighting some of the features with black embroidary or applique. This could be used to help define some of the areas, such as the beard/leaves at the bottom of the face and perhaps some leafy eyebrows.

This pattern could also be adapted for construction using strips, cut by a rotary cutter. Just work out the number of blocks in each "strip" of colour and cut accordingly. It would sped up construction of the quilt considerably!

This quilt would look good with quilting that outlines the central image or perhaps some leafy or garland type pattern.